1 1321 130 DEMONSTRATION AND CHARACTERIZATION OF MUTATIONS INDUCED BY HELICOBACTER PYLORI ORGANISMS IN GASTRIC EPITHELIAL CELLS. BACKGROUND: HELICOBACTER PYLORI GASTRITIS INCREASES GASTRIC CANCER RISK. MICROSATELLITE INSTABILITY-TYPE MUTATIONS ARE SECONDARY TO DEFICIENT DNA MISMATCH REPAIR. H. PYLORI GASTRITIS IS MORE FREQUENT IN PATIENTS WITH MICROSATELLITE INSTABILITY-POSITIVE GASTRIC CANCERS, AND H. PYLORI ORGANISMS INDEPENDENTLY OF INFLAMMATION CAN REDUCE DNA MISMATCH REPAIR PROTEIN LEVELS, RAISING THE HYPOTHESIS THAT H. PYLORI ORGANISMS MIGHT LEAD TO MUTAGENESIS DURING INFECTION. MATERIALS AND METHODS: MUTATIONS WERE DETECTED USING A GREEN FLUORESCENT PROTEIN REPORTER VECTOR (PEGFP-CA13). GASTRIC CANCER AGS CELLS TRANSFECTED WITH PEGFP-CA13 WERE COCULTURED WITH H. PYLORI OR ESCHERICHIA COLI. THE NUMBERS OF GREEN FLUORESCENT PROTEIN (GFP)-POSITIVE CELLS WERE DETERMINED, AND GFP, HMSH2, AND HMLH1 PROTEIN LEVELS WERE MEASURED BY WESTERN BLOT. THE EFFECT OF H. PYLORI ON CPG METHYLATION STATUS OF HMLH1 WAS DETERMINED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. RESULTS: GFP LEVELS AND GFP-POSITIVE CELL NUMBERS IN AGS CELLS COCULTURED WITH H. PYLORI SIGNIFICANTLY INCREASED, AS THE LEVELS OF HMLH1 AND HMSH2 DROPPED. H. PYLORI COCULTURES INDUCED LOW-LEVEL CPG METHYLATION OF THE HMLH1 PROMOTER. SEQUENCE ANALYSIS OF CELLS COCULTURED WITH H. PYLORI SHOWED AN INCREASED NUMBER OF FRAMESHIFT MUTATIONS AND POINT MUTATIONS AS COMPARED TO CELLS NOT COCULTURED WITH H. PYLORI (P = .03 AND P = .001, RESPECTIVELY). CONCLUSIONS: THIS IS THE FIRST REPORT SHOWING THAT H. PYLORI BACTERIA MAY LEAD TO ACCUMULATION OF GENOMIC MUTATIONS, INDEPENDENTLY OF UNDERLYING INFLAMMATION. THIS IS ASSOCIATED WITH REDUCED DNA MISMATCH REPAIR, AND IS AT LEAST IN PART ASSOCIATED WITH CPG METHYLATION OF THE HMLH1 PROMOTER. THESE DATA SUPPORT THE NOTION THAT H. PYLORI-INDUCED MUTATIONS AND EPIGENETIC ALTERATIONS IN GASTRIC EPITHELIAL CELLS DURING CHRONIC GASTRITIS MAY CONTRIBUTE TO AN INCREASED RISK OF GASTRIC CANCER ASSOCIATED WITH H. PYLORI INFECTION. 2006 2 4102 29 MDR1-P-GLYCOPROTEIN BEHAVES AS AN ONCOFETAL PROTEIN THAT PROMOTES CELL SURVIVAL IN GASTRIC CANCER CELLS. P-GLYCOPROTEIN (P-GP), TRADITIONALLY LINKED TO CANCER POOR PROGNOSIS AND MULTIDRUG RESISTANCE, IS UNDETECTABLE IN NORMAL GASTRIC MUCOSA AND OVEREXPRESSED IN GASTRIC CANCER (GC). WE PROPOSE THAT P-GP MAY BE INVOLVED IN HELICOBACTER PYLORI (HP)-RELATED GASTRIC CARCINOGENESIS BY INHIBITING APOPTOSIS. AIM OF THE STUDY WAS TO EVALUATE THE EXPRESSION OF P-GP IN FETAL STOMACH AND IN HP-RELATED GASTRIC CARCINOGENESIS, THE EPIGENETIC CONTROL OF THE MULTI-DRUG RESISTANCE-1 (MDR1) GENE, THE LOCALIZATION AND INTERACTION BETWEEN P-GP AND BCL-X(L) AND THE EFFECT OF THE SELECTIVE SILENCING OF P-GP ON CELL SURVIVAL. P-GP AND BCL-XL EXPRESSION WAS EVALUATED BY IMMUNOHISTOCHEMISTRY ON 28 SPONTANEOUSLY ABORTIVE HUMAN FETUSES, 66 HP-NEGATIVE SUBJECTS, 138 HP-POSITIVE CHRONIC GASTRITIS (CG) OF WHOM 28 WITH INTESTINAL METAPLASIA (IM) AND 45 INTESTINAL TYPE GCS. P-GP/BCL-X(L) COLOCALIZATION WAS INVESTIGATED BY CONFOCAL IMMUNOFLUORESCENCE MICROSCOPY AND PROTEIN-PROTEIN INTERACTION BY CO-IMMUNOPRECIPITATION, IN BASAL CONDITIONS AND AFTER STRESS-INDUCED APOPTOSIS, IN GC CELL LINES AGS AND MKN-28 AND HEPATOCELLULAR CARCINOMA CELL LINE HEP-G2. THE ROLE OF P-GP IN CONTROLLING APOPTOSIS WAS EVALUATED BY KNOCKING DOWN ITS EXPRESSION WITH A SPECIFIC SMALL INTERFERING RNAS IN STRESSED AGS AND MKN-28 CELL LINES. P-GP IS EXPRESSED IN THE GASTRIC MUCOSA OF ALL HUMAN FETUSES WHILE, IT IS UNDETECTABLE IN ADULT NORMAL MUCOSA AND RE-EXPRESSED IN 30/110 HP-POSITIVE NON-IM-CG, 28/28 IM-CG AND 40/45 GCS. P-GP EXPRESSION DIRECTLY CORRELATES WITH THAT OF BCL-X(L) AND WITH THE PROMOTER HYPOMETHYLATION OF THE MDR1 GENE. IN GC CELL LINES, P-GP IS LOCALIZED ON THE PLASMA MEMBRANE AND MITOCHONDRIA WHERE IT COLOCALIZES WITH BCL-X(L). CO-IMMUNOPRECIPITATION CONFIRMS THE PHYSICAL INTERACTION BETWEEN P-GP AND BCL-X(L) IN AGS, MKN-28 AND HEP-G2, AT BOTH BASAL LEVEL AND AFTER STRESS-INDUCED APOPTOSIS. THE SELECTIVE SILENCING OF P-GP SENSITIZES GC CELLS TO STRESS-INDUCED APOPTOSIS. P-GP BEHAVES AS AN ONCOFETAL PROTEIN THAT, BY CROSS-TALKING WITH BCL-X(L), ACTS AS AN ANTI-APOPTOTIC AGENT IN HP-RELATED GASTRIC CARCINOGENESIS. 2012 3 3037 33 GENOME AND METHYLOME VARIATION IN HELICOBACTER PYLORI WITH A CAG PATHOGENICITY ISLAND DURING EARLY STAGES OF HUMAN INFECTION. BACKGROUND & AIMS: HELICOBACTER PYLORI IS REMARKABLE FOR ITS GENETIC VARIATION; YET, LITTLE IS KNOWN ABOUT ITS GENETIC CHANGES DURING EARLY STAGES OF HUMAN INFECTION, AS THE BACTERIA ADAPT TO THEIR NEW ENVIRONMENT. WE ANALYZED GENOME AND METHYLOME VARIATIONS IN A FULLY VIRULENT STRAIN OF H PYLORI DURING EXPERIMENTAL INFECTION. METHODS: WE PERFORMED A RANDOMIZED PHASE I/II, OBSERVER-BLIND, PLACEBO-CONTROLLED STUDY OF 12 HEALTHY, H PYLORI-NEGATIVE ADULTS IN GERMANY FROM OCTOBER 2008 THROUGH MARCH 2010. THE VOLUNTEERS WERE GIVEN A PROPHYLACTIC VACCINE CANDIDATE (N = 7) OR PLACEBO (N = 5) AND THEN CHALLENGED WITH H PYLORI STRAIN BCM-300. BIOPSY SAMPLES WERE COLLECTED AND H PYLORI WERE ISOLATED. GENOMES OF THE CHALLENGE STRAIN AND 12 REISOLATES, OBTAINED 12 WEEKS AFTER (OR IN 1 CASE, 62 WEEKS AFTER) INFECTION WERE SEQUENCED BY SINGLE-MOLECULE, REAL-TIME TECHNOLOGY, WHICH, IN PARALLEL, PERMITTED DETERMINATION OF GENOME-WIDE METHYLATION PATTERNS FOR ALL STRAINS. FUNCTIONAL EFFECTS OF GENETIC CHANGES OBSERVED IN H PYLORI STRAINS DURING HUMAN INFECTION WERE ASSESSED BY MEASURING RELEASE OF INTERLEUKIN 8 FROM AGS CELLS (TO DETECT CAG PATHOGENICITY ISLAND FUNCTION), NEUTRAL RED UPTAKE (TO DETECT VACUOLATING CYTOTOXIN ACTIVITY), AND ADHESION ASSAYS. RESULTS: THE OBSERVED MUTATION RATE WAS IN AGREEMENT WITH RATES PREVIOUSLY DETERMINED FROM PATIENTS WITH CHRONIC H PYLORI INFECTIONS, WITHOUT EVIDENCE OF A MUTATION BURST. A LOSS OF CAG PATHOGENICITY ISLAND FUNCTION WAS OBSERVED IN 3 REISOLATES. IN ADDITION, 3 REISOLATES FROM THE VACCINE GROUP ACQUIRED MUTATIONS IN THE VACUOLATING CYTOTOXIN GENE VACA, RESULTING IN LOSS OF VACUOLIZATION ACTIVITY. WE OBSERVED INTERSTRAIN VARIATION IN METHYLOMES DUE TO PHASE VARIATION IN GENES ENCODING METHYLTRANSFERASES. CONCLUSIONS: WE ANALYZED ADAPTATION OF A FULLY VIRULENT STRAIN OF H PYLORI TO 12 DIFFERENT VOLUNTEERS TO OBTAIN A ROBUST ESTIMATE OF THE FREQUENCY OF GENETIC AND EPIGENETIC CHANGES IN THE ABSENCE OF INTERSTRAIN RECOMBINATION. OUR FINDINGS INDICATE THAT THE LARGE AMOUNT OF GENETIC VARIATION IN H PYLORI POSES A CHALLENGE TO VACCINE DEVELOPMENT. CLINICALTRIALS.GOV NO: NCT00736476. 2018 4 3231 39 HELICOBACTER PYLORI-INDUCED MODULATION OF THE PROMOTER METHYLATION OF WNT ANTAGONIST GENES IN GASTRIC CARCINOGENESIS. BACKGROUND: THIS STUDY AIMED TO INVESTIGATE THE CHANGES IN THE PROMOTER METHYLATION AND GENE EXPRESSION OF MULTIPLE WNT ANTAGONISTS BETWEEN THE CHRONIC INFECTION AND ERADICATION OF HELICOBACTER PYLORI (H. PYLORI) IN GASTRIC CARCINOGENESIS. METHODS: THE LEVELS OF METHYLATION AND CORRESPONDING MRNA EXPRESSION OF SEVEN WNT ANTAGONIST GENES (SFRP1, -2, -5, DKK1, -2, -3, WIF1) WERE COMPARED AMONG THE PATIENTS WITH H. PYLORI-POSITIVE GASTRIC CANCERS (GCS), AND H. PYLORI-POSITIVE AND H. PYLORI-NEGATIVE CONTROLS, BY QUANTITATIVE METHYLIGHT ASSAY AND REAL-TIME REVERSE TRANSCRIPTION (RT)-POLYMERASE CHAIN REACTION (PCR), RESPECTIVELY. THE CHANGES OF THE METHYLATION AND EXPRESSION LEVELS OF THE GENES WERE ALSO COMPARED BETWEEN THE H. PYLORI ERADICATION AND H. PYLORI-PERSISTENT GROUPS 1 YEAR AFTER ENDOSCOPIC RESECTION OF GCS. RESULTS: THE METHYLATION LEVELS OF SFRP AND DKK FAMILY GENES WERE SIGNIFICANTLY INCREASED IN THE PATIENTS WITH H. PYLORI-POSITIVE GCS AND FOLLOWED BY H. PYLORI-POSITIVE CONTROLS COMPARED WITH H. PYLORI-NEGATIVE CONTROLS (P < 0.001). SFRP1, -2, AND DKK3 GENE EXPRESSION WAS STEPWISE DOWNREGULATED FROM H. PYLORI-NEGATIVE CONTROLS, H. PYLORI-POSITIVE CONTROLS, AND TO H. PYLORI-POSITIVE GCS (P < 0.05). AMONG THE WNT ANTAGONISTS, ONLY THE DEGREES OF METHYLATION AND DOWNREGULATION OF DKK3 WERE SIGNIFICANTLY REDUCED AFTER H. PYLORI ERADICATION (P < 0.05). CONCLUSION: EPIGENETIC SILENCING OF SFRP AND DKK FAMILY GENES MAY FACILITATE THE FORMATION OF AN EPIGENETIC FIELD DURING H. PYLORI-ASSOCIATED GASTRIC CARCINOGENESIS. THE EPIGENETIC FIELD MAY NOT BE REVERSED EVEN AFTER H. PYLORI ERADICATION EXCEPT BY DKK3 METHYLATION. 2018 5 3134 41 GLOBAL DNA HYPOMETHYLATION IS AN EARLY EVENT IN HELICOBACTER PYLORI-RELATED GASTRIC CARCINOGENESIS. AIM: CANCER, PARTICULARLY GASTRIC CANCER (GC), IS PREVALENTLY AN EPIGENETIC PHENOMENON THAT IS DEPENDENT ON AN ALTERED DNA METHYLATION PATTERN. IN GASTRIC CARCINOGENESIS, MANY GENES SHOW ABERRANT METHYLATION; HOWEVER, NONE OF THEM MAY BE USED AS A BIOMARKER OF CANCER RISK AND PROGRESSION. THE AUTHORS AIMED TO EVALUATE THE GLOBAL DNA METHYLATION OF GASTRIC MUCOSA IN HELICOBACTER PYLORI (HP)-RELATED CHRONIC GASTRITIS, IN GC AND IN 10 PATIENTS WITH PRENEOPLASTIC LESIONS (IE, ATROPHY AND INTESTINAL METAPLASIA) FOLLOWED UP FOR 10 YEARS. METHODS: THE AUTHORS ANALYSED 93 DYSPEPTIC PATIENTS WHO UNDERWENT UPPER ENDOSCOPY, 41 SURGICAL GC SAMPLES AND 10 PATIENTS WITH PRENEOPLASTIC GASTRIC LESIONS FOLLOWED UP FOR 10 YEARS AFTER SUCCESSFUL HP ERADICATION THERAPY. GLOBAL DNA METHYLATION STATUS AND SURROGATE MARKERS OF CELL PROLIFERATION AND APOPTOSIS WERE EVALUATED BY IMMUNOHISTOCHEMISTRY USING THE ANTI-5-METHYLCYTOSINE (5-MC), ANTI-KI-67 AND ANTI-P53 (ANTI-APOPTOTIC MARKER)-SPECIFIC ANTIBODIES, RESPECTIVELY. RESULTS: GLOBAL DNA METHYLATION OF GASTRIC MUCOSA GRADUALLY DECREASED FROM NORMAL MUCOSA TO HP-POSITIVE GASTRITIS, HP-POSITIVE CHRONIC ATROPHIC GASTRITIS, INDEPENDENT OF CAG-A STATUS AND GC; HOWEVER, THE VARIATION WAS SIGNIFICANT (P<0.05) ONLY BETWEEN HP-NEGATIVE SUBJECTS AND HP-POSITIVE CHRONIC GASTRITIS. INTERESTINGLY, THE 5-MC IMMUNOSTAINING WAS ABSENT IN AREAS OF INTESTINAL METAPLASIA. IN THE 10 PATIENTS WITH PRENEOPLASTIC LESIONS, GLOBAL DNA METHYLATION DECREASED OVER TIME DESPITE THE ERADICATION OF HP INFECTION, BUT REACHED SIGNIFICANCE ONLY AT 10 YEARS VERSUS BASELINE. THE 5-MC IMMUNOSTAINING NEGATIVELY CORRELATED WITH KI-67 AND P53 EXPRESSION IN ALL GROUPS. CONCLUSION: GLOBAL DNA HYPOMETHYLATION IS AN EARLY MOLECULAR EVENT IN HP-RELATED GASTRIC CARCINOGENESIS. FURTHER STUDIES WITH MORE CASES AND A LONGER FOLLOW-UP ARE NEEDED TO ESTABLISH THE POTENTIAL GC PREDICTIVE ROLE OF DNA HYPOMETHYLATION. 2011 6 3227 40 HELICOBACTER PYLORI INFECTION-INDUCED H3SER10 PHOSPHORYLATION IN STEPWISE GASTRIC CARCINOGENESIS AND ITS CLINICAL IMPLICATIONS. BACKGROUND: OUR PREVIOUS WORKS HAVE DEMONSTRATED THAT HELICOBACTER PYLORI (HP) INFECTION CAN ALTER HISTONE H3 SERINE 10 PHOSPHORYLATION STATUS IN GASTRIC EPITHELIAL CELLS. HOWEVER, WHETHER HELICOBACTER PYLORI-INDUCED HISTONE H3 SERINE 10 PHOSPHORYLATION PARTICIPATES IN GASTRIC CARCINOGENESIS IS UNKNOWN. WE INVESTIGATE THE EXPRESSION OF HISTONE H3 SERINE 10 PHOSPHORYLATION IN VARIOUS STAGES OF GASTRIC DISEASE AND EXPLORE ITS CLINICAL IMPLICATION. MATERIALS AND METHODS: STOMACH BIOPSY SAMPLES FROM 129 PATIENTS WERE COLLECTED AND STAINED WITH HISTONE H3 SERINE 10 PHOSPHORYLATION, KI67, AND HELICOBACTER PYLORI BY IMMUNOHISTOCHEMISTRY STAINING, EXPRESSED AS LABELING INDEX. THEY WERE CATEGORIZED INTO NONATROPHIC GASTRITIS, CHRONIC ATROPHIC GASTRITIS, INTESTINAL METAPLASIA, LOW-GRADE INTRAEPITHELIAL NEOPLASIA, HIGH-GRADE INTRAEPITHELIAL NEOPLASIA, AND INTESTINAL-TYPE GASTRIC CANCER GROUPS. HELICOBACTER PYLORI INFECTION WAS DETERMINED BY EITHER (13) C-UREA BREATH TEST OR IMMUNOHISTOCHEMISTRY STAINING. RESULTS: IN HELICOBACTER PYLORI-NEGATIVE PATIENTS, LABELING INDEX OF HISTONE H3 SERINE 10 PHOSPHORYLATION WAS GRADUALLY INCREASED IN NONATROPHIC GASTRITIS, CHRONIC ATROPHIC GASTRITIS, INTESTINAL METAPLASIA GROUPS, PEAKED AT LOW-GRADE INTRAEPITHELIAL NEOPLASIA, AND DECLINED IN HIGH-GRADE INTRAEPITHELIAL NEOPLASIA AND GASTRIC CANCER GROUPS. IN HELICOBACTER PYLORI-INFECTED PATIENTS, LABELING INDEX OF HISTONE H3 SERINE 10 PHOSPHORYLATION FOLLOWED THE SIMILAR PATTERN AS ABOVE, WITH INCREASED EXPRESSION OVER THE CORRESPONDING HELICOBACTER PYLORI-NEGATIVE CONTROLS EXCEPT IN NONATROPHIC GASTRITIS PATIENT WHOSE LABELING INDEX WAS DECREASED WHEN COMPARED WITH HELICOBACTER PYLORI-NEGATIVE CONTROL. LABELING INDEX OF KI67 IN HELICOBACTER PYLORI-NEGATIVE GROUPS WAS HIGHER IN GASTRIC CANCER THAN CHRONIC ATROPHIC GASTRITIS AND LOW-GRADE INTRAEPITHELIAL NEOPLASIA GROUPS, AND HIGHER IN INTESTINAL METAPLASIA GROUP COMPARED WITH CHRONIC ATROPHIC GASTRITIS GROUP. IN HELICOBACTER PYLORI-POSITIVE GROUPS, KI67 LABELING INDEX WAS INCREASED STEPWISE FROM NONATROPHIC GASTRITIS TO GASTRIC CANCER EXCEPT SLIGHTLY DECREASE IN CHRONIC ATROPHIC GASTRITIS GROUP. IN ADDITION, WE NOTED THAT HISTONE H3 SERINE 10 PHOSPHORYLATION STAINING IS ACCOMPANIED WITH ITS LOCATION CHANGES FROM GASTRIC GLAND BOTTOM EXPANDED TO WHOLE GLAND AS DISEASE STAGE PROGRESS. CONCLUSIONS: THESE RESULTS INDICATE THAT STEPWISE GASTRIC CARCINOGENESIS IS ASSOCIATED WITH ALTERED HISTONE H3 SERINE 10 PHOSPHORYLATION, HELICOBACTER PYLORI INFECTION ENHANCES HISTONE H3 SERINE 10 PHOSPHORYLATION EXPRESSION IN THESE PROCESSES; IT IS ALSO ACCOMPANIED WITH HISTONE H3 SERINE 10 PHOSPHORYLATION LOCATION CHANGE FROM GLAND BOTTOM STAINING EXPAND TO WHOLE GLAND EXPRESSION. THE RESULTS SUGGEST THAT EPIGENETIC DYSREGULATION MAY PLAY IMPORTANT ROLES IN HELICOBACTER PYLORI-INDUCED GASTRIC CANCER. 2018 7 672 37 BRAF, KRAS AND HELICOBACTER PYLORI EPIGENETIC CHANGES-ASSOCIATED CHRONIC GASTRITIS IN EGYPTIAN PATIENTS WITH AND WITHOUT GASTRIC CANCER. WE AIMED TO STUDY MLH1 AND MGMT METHYLATION STATUS IN HELICOBACTER PYLORI-ASSOCIATED CHRONIC GASTRITIS IN EGYPTIAN PATIENTS WITH AND WITHOUT GASTRIC CANCER. 39 PATIENTS WERE INCLUDED IN OUR STUDY. THEY WERE DIVIDED INTO 2 GROUPS; PATIENTS WITHOUT (GROUP I) AND WITH GASTRIC ADENOCARCINOMA (GROUP II). PATIENTS WERE SUBJECTED TO CLINICAL EXAMINATION, ABDOMINAL ULTRASOUND AND UPPER ENDOSCOPY FOR GASTRIC BIOPSY. BIOPSIES WERE SUBJECTED TO UREASE TEST, HISTOLOGICAL EXAMINATION, AND DNA PURIFICATION. H. PYLORI, BRAF, KRAS, MLH1 AND MGMT METHYLATION WERE ASSESSED BY QUANTITATIVE PCR. DNA SEQUENCING WAS PERFORMED TO ASSESS BRAF AND KRAS GENES MUTATION. QPCR OF H. PYLORI WAS SIGNIFICANTLY HIGHER IN PATIENTS WITH ADENOCARCINOMA (GROUP II) THAN THOSE WITHOUT ADENOCARCINOMA (GROUP I); WITH A P < 0.001 AS WELL AS IN PATIENTS WITH AGE ABOVE 50 YEARS WITH A P VALUE = 0.008. BY APPLYING LOGISTIC REGRESSION ANALYSIS IT WAS REPORTED THAT THE H. PYLORI QPCR IS A SIGNIFICANT PREDICTOR TO THE ADENOCARCINOMA WITH OR = 1.025 (95 % CI: 1. 002-1.048), WITH SENSITIVITY OF 90 % AND SPECIFICITY OF 100 %. ADENOCARCINOMA PATIENTS HAD A SIGNIFICANTLY HIGHER MEAN AGE AND LEVELS OF H. PYLORI, BRAF, K-RAS, METHYLATED MGMT AND METHYLATED MLH1 THAN THOSE OF GASTRITIS PATIENTS. DNA SEQUENCE ANALYSIS OF BRAF (CODON 12) AND KRAS (CODON 600) HAD GENES MUTATION IN GASTRIC ADENOCARCINOMA VERSUS CHRONIC GASTRITIS. CONCLUSION: H. PYLORI MAY CAUSE EPIGENETIC CHANGES PREDISPOSING THE PATIENTS TO CANCER STOMACH. ESTIMATION OF H. PYLORI BY QPCR CAN BE A GOOD PREDICTOR TO ADENOCARCINOMA. BRAF AND KRAS GENES MUTATION WERE REVELED IN GASTRITIS AND ADENOCARCINOMA PATIENTS. 2016 8 526 34 ASSOCIATIONS OF HELICOBACTER PYLORI INFECTION AND CHRONIC ATROPHIC GASTRITIS WITH ACCELERATED EPIGENETIC AGEING IN OLDER ADULTS. BACKGROUND: HELICOBACTER PYLORI (HP) INFECTION AND CHRONIC ATROPHIC GASTRITIS (CAG) HAVE SHOWN STRONG ASSOCIATIONS WITH THE DEVELOPMENT OF GASTRIC CANCER. THIS STUDY AIMED TO EXAMINE WHETHER BOTH RISK FACTORS ARE ASSOCIATED WITH ACCELERATED EPIGENETIC AGEING, AS DETERMINED BY THE 'DNA METHYLATION AGE', IN A POPULATION-BASED STUDY OF OLDER ADULTS (N=1477). METHODS: SEROLOGICAL MEASUREMENTS OF HP ANTIBODIES AND PEPSINOGEN I AND II FOR CAG DEFINITION WERE OBTAINED BY ELISA KITS. WHOLE BLOOD DNA METHYLATION PROFILES WERE MEASURED BY ILLUMINA HUMAN METHYLATION450K BEADCHIP. DNA METHYLATION AGES WERE CALCULATED BY TWO ALGORITHMS PROPOSED BY HORVATH AND HANNUM ET AL. RESULTS: AFTER ADJUSTING FOR POTENTIAL COVARIATES IN LINEAR REGRESSION MODELS, WE FOUND THAT HP INFECTION, INFECTION WITH VIRULENT HP STRAINS (CAGA+) AND SEVERE CAG WERE SIGNIFICANTLY ASSOCIATED WITH AN INCREASE IN DNA METHYLATION AGE BY APPROXIMATELY 0.4, 0.6 AND 1 YEAR (ALL P-VALUES <0.05), RESPECTIVELY. CONCLUSIONS: OUR STUDY INDICATES THAT BOTH CAGA+ HP INFECTION AND CAG GO ALONG WITH ACCELERATED EPIGENETIC AGEING. 2017 9 2439 40 EPIGENETIC SILENCING OF THE MLH1 PROMOTER IN RELATION TO THE DEVELOPMENT OF GASTRIC CANCER AND ITS USE AS A BIOMARKER FOR PATIENTS WITH MICROSATELLITE INSTABILITY: A SYSTEMATIC ANALYSIS. BACKGROUND/AIMS: HUMAN MUTL HOMOLOG 1 (MLH1) PROMOTER METHYLATION WAS REPORTED IN GASTRIC CANCER (GC). THIS STUDY DETERMINED THE CLINICOPATHOLOGICAL, PROGNOSTIC, AND DIAGNOSTIC EFFECTS OF MLH1 PROMOTER METHYLATION IN GC. METHODS: THE COMBINED ODDS RATIO (OR) OR HAZARD RATIO (HR) AND THEIR CORRESPONDING 95% CONFIDENCE INTERVALS (95% CI) WERE CALCULATED. THE POOLED SENSITIVITY, SPECIFICITY, AND AREA UNDER THE CURVE (AUC) WERE ANALYZED. RESULTS: A TOTAL OF 4654 GC PATIENTS AND 3669 NON-MALIGNANT CONTROLS WERE IDENTIFIED IN THIS SYSTEMATIC ANALYSIS. MLH1 PROMOTER METHYLATION WAS SIGNIFICANTLY HIGHER IN GC SAMPLES THAN IN GASTRIC ADENOMAS, CHRONIC GASTRITIS, ADJACENT TISSUES, NORMAL GASTRIC MUCOSA, AND NORMAL HEALTHY BLOOD SAMPLES, BUT IT EXHIBITED A SIMILAR FREQUENCY IN GC VS. INTESTINAL METAPLASIA AND DYSPLASIA SAMPLES. MLH1 PROMOTER METHYLATION CORRELATED WITH AGE AND MICROSATELLITE INSTABILITY (MSI), BUT IT WAS NOT ASSOCIATED WITH GENDER, H. PYLORI INFECTION, SMOKING, DRINKING BEHAVIORS, PATHOLOGICAL HISTOLOGY, TUMOR DIFFERENTIATION, CLINICAL STAGE, LYMPH NODE STATUS, DISTANT METASTASIS, OR OVERALL SURVIVAL OF GC. MLH1 PROMOTER METHYLATION EXHIBITED A POOR SENSITIVITY VALUE (< 0.5) IN PATIENTS WITH GC COMPARED WITH ADJACENT TISSUES, GASTRIC ADENOMAS, CHRONIC GASTRITIS, NORMAL GASTRIC MUCOSA, AND NORMAL HEALTHY BLOOD SAMPLES. THE POOLED SENSITIVITY, SPECIFICITY, AND AUC OF MLH1 PROMOTER METHYLATION IN GC WITH MSI VS. GC WITH MICROSATELLITE STABILITY (MSS) SAMPLES WERE 0.64, 0.96, AND 0.90, RESPECTIVELY. CONCLUSIONS: OUR RESULTS SUGGEST THAT THE DETECTION OF MLH1 PROMOTER METHYLATION MAY BE A POTENTIAL PROGNOSTIC BIOMARKER FOR GC PATIENTS WITH MSI. 2018 10 4248 46 METHYLATION STATUS, MRNA AND PROTEIN EXPRESSION OF THE SMAD4 GENE IN PATIENTS WITH NON-MELANOCYTIC SKIN CANCERS. BACKGROUND: SMAD4 IS A POTENT TUMOR SUPPRESSOR. SMAD4 LOSS INCREASES GENOMIC INSTABILITY AND PLAYS A CRITICAL ROLE IN THE DNA DAMAGE RESPONSE THAT LEADS TO SKIN CANCER DEVELOPMENT. WE AIMED TO INVESTIGATE SMAD4 METHYLATION EFFECTS ON MRNA AND PROTEIN EXPRESSION OF SMAD4 IN CANCER AND HEALTHY TISSUES FROM PATIENTS WITH BASAL CELL CARCINOMA (BCC), CUTANEOUS SQUAMOUS CELL CARCINOMA (CSCC), AND BASOSQUAMOUS SKIN CANCER (BSC). METHODS AND RESULTS: THE STUDY INCLUDED 17 BCC, 24 CSCC AND NINE BSC PATIENTS. DNA AND RNA WERE ISOLATED FROM CANCEROUS AND HEALTHY TISSUES FOLLOWING PUNCH BIOPSY. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) AND REAL-TIME QUANTITATIVE PCR METHODS WERE USED TO EXAMINE SMAD4 PROMOTER METHYLATION AND SMAD4 MRNA LEVELS, RESPECTIVELY. THE PERCENTAGE AND INTENSITY OF STAINING OF THE SMAD4 PROTEIN WERE DETERMINED BY IMMUNOHISTOCHEMISTRY. THE PERCENTAGE OF SMAD4 METHYLATION WAS INCREASED IN THE PATIENTS WITH BCC (P = 0.007), CSCC (P = 0.004), AND BSC (P = 0.018) COMPARED TO THE HEALTHY TISSUE. SMAD4 MRNA EXPRESSION WAS DECREASED IN THE PATIENTS WITH BCC (P<0.001), CSCC (P<0.001), AND BSC (P = 0.008). THE STAINING CHARACTERISTIC OF SMAD4 PROTEIN WAS NEGATIVE IN THE CANCER TISSUES OF THE PATIENTS WITH CSCC (P = 0.00). LOWER SMAD4 MRNA LEVELS WERE OBSERVED IN THE POORLY DIFFERENTIATED CSCC PATIENTS (P = 0.001). THE STAINING CHARACTERISTICS OF THE SMAD4 PROTEIN WERE RELATED TO AGE AND CHRONIC SUN EXPOSURE. CONCLUSIONS: HYPERMETHYLATION OF SMAD4 AND REDUCED SMAD4 MRNA EXPRESSION WERE FOUND TO PLAY A ROLE IN THE PATHOGENESIS OF BCC, CSCC, AND BSC. A DECREASE IN SMAD4 PROTEIN EXPRESSION LEVEL WAS OBSERVED ONLY IN CSCC PATIENTS. THIS SUGGESTS THAT EPIGENETIC ALTERATIONS TO THE SMAD4 GENE ARE ASSOCIATED WITH CSCC. TRIAL REGISTRATION: THE NAME OF THE TRIAL REGISTER: SMAD4 METHYLATION AND EXPRESSION LEVELS IN NON-MELANOCYTIC SKIN CANCERS; SMAD4 PROTEIN POSITIVITY. THE REGISTRATION NUMBER: NCT04759261 ( HTTPS://CLINICALTRIALS.GOV/CT2/RESULTS?TERM=NCT04759261 ). 2023 11 4231 44 METHYLATION OF PROTOCADHERIN 10, A NOVEL TUMOR SUPPRESSOR, IS ASSOCIATED WITH POOR PROGNOSIS IN PATIENTS WITH GASTRIC CANCER. BACKGROUND & AIMS: BY USING METHYLATION-SENSITIVE REPRESENTATIONAL DIFFERENCE ANALYSIS, WE IDENTIFIED PROTOCADHERIN 10 (PCDH10), A GENE THAT ENCODES A PROTOCADHERIN AND IS SILENCED IN A TUMOR-SPECIFIC MANNER. WE ANALYZED ITS EPIGENETIC INACTIVATION, BIOLOGICAL EFFECTS, AND PROGNOSTIC SIGNIFICANCE IN GASTRIC CANCER. METHODS: METHYLATION STATUS WAS EVALUATED BY COMBINED BISULFITE RESTRICTION ANALYSIS AND BISULFITE SEQUENCING. THE EFFECTS OF PCDH10 RE-EXPRESSION WERE DETERMINED IN GROWTH, APOPTOSIS, PROLIFERATION, AND INVASION ASSAYS. PCDH10 TARGET GENES WERE IDENTIFIED BY COMPLEMENTARY DNA MICROARRAY ANALYSIS. RESULTS: PCDH10 WAS SILENCED OR DOWN-REGULATED IN 94% (16 OF 17) OF GASTRIC CANCER CELL LINES; EXPRESSION LEVELS WERE RESTORED BY EXPOSURE TO DEMETHYLATING AGENTS. RE-EXPRESSION OF PCDH10 IN MKN45 GASTRIC CANCER CELLS REDUCED COLONY FORMATION IN VITRO AND TUMOR GROWTH IN MICE; IT ALSO INHIBITED CELL PROLIFERATION (P < .01), INDUCED CELL APOPTOSIS (P < .001), AND REPRESSED CELL INVASION (P < .05), UP-REGULATING THE PRO-APOPTOSIS GENES FAS, CASPASE 8, JUN, AND CDKN1A; THE ANTIPROLIFERATION GENE FGFR; AND THE ANTI-INVASION GENE HTATIP2. PCDH10 METHYLATION WAS DETECTED IN 82% (85 OF 104) OF GASTRIC TUMORS COMPARED WITH 37% (38 OF 104) OF PAIRED NONTUMOR TISSUES (P < .0001). IN THE LATTER, PCDH10 METHYLATION WAS HIGHER IN PRECANCEROUS LESIONS (27 OF 45; 60%) THAN IN CHRONIC GASTRITIS SAMPLES (11 OF 59; 19%) (P < .0001). AFTER A MEDIAN FOLLOW-UP PERIOD OF 16.8 MONTHS, MULTIVARIATE ANALYSIS REVEALED THAT PATIENTS WITH PCDH10 METHYLATION IN ADJACENT NONTUMOR AREAS HAD A SIGNIFICANT DECREASE IN OVERALL SURVIVAL. KAPLAN-MEIER SURVIVAL CURVES SHOWED THAT PCDH10 METHYLATION WAS ASSOCIATED SIGNIFICANTLY WITH SHORTENED SURVIVAL IN STAGE I-III GASTRIC CANCER PATIENTS. CONCLUSIONS: PCDH10 IS A GASTRIC TUMOR SUPPRESSOR; ITS METHYLATION AT EARLY STAGES OF GASTRIC CARCINOGENESIS IS AN INDEPENDENT PROGNOSTIC FACTOR. 2009 12 1797 37 EFFECT OF HELICOBACTER PYLORI ERADICATION ON GASTRIC PRECANCEROUS LESIONS: A SYSTEMATIC REVIEW AND META-ANALYSIS. BACKGROUND: THE QUESTION OF WHETHER ERADICATION OF HELICOBACTER PYLORI (HP) CAN REVERSE GASTRIC PRECANCEROUS LESIONS, INCLUDING INTESTINAL METAPLASIA, REMAINS UNCERTAIN, LEADING TO ONGOING DEBATE. THEREFORE, A META-ANALYSIS WAS PERFORMED TO EVALUATE THE EFFECT OF HP ERADICATION ON GASTRIC PRECANCEROUS LESIONS. MATERIALS AND METHODS: PUBMED, EMBASE, COCHRANE LIBRARY, WEB OF SCIENCE, SCOPUS DATABASE, AND CLINICALTRIALS.GOV WERE SYSTEMATICALLY SEARCHED FROM INCEPTION TO APRIL 2023 FOR STUDIES THAT EXPLORED THE IMPACT OF HP ERADICATION ON GASTRIC PRECANCEROUS LESIONS. RISK RATIOS (RRS) AND THEIR 95% CONFIDENCE INTERVALS (95% CIS) WERE SELECTED AS THE EFFECT SIZE. WE USED THE RANDOM-EFFECTS MODEL TO ASSESS POOLED DATA. WE ALSO PERFORMED QUALITY ASSESSMENTS, SUBGROUP ANALYSES, AND SENSITIVITY ANALYSES. RESULTS: FIFTEEN STUDIES WERE INCLUDED. COMPARED WITH PLACEBO, HP ERADICATION COULD SIGNIFICANTLY PREVENT THE PROGRESSION OF GASTRIC PRECANCEROUS LESIONS (RR = 0.87, 95% CI: 0.81-0.94, P < 0.01) AND REVERSE THEM (RR = 1.32, 95% CI: 1.17-1.50, P < 0.01). THEN, SPECIFIC PRECANCEROUS LESIONS WERE FURTHER EXPLORED. THE PROGRESSION OF INTESTINAL METAPLASIA WAS SIGNIFICANTLY PREVENTED BY HP ERADICATION COMPARED TO PLACEBO OR NO TREATMENT (RR = 0.80, 95% CI: 0.69-0.94, P < 0.01). MOREOVER, COMPARED WITH PLACEBO OR NO TREATMENT, HP ERADICATION ALSO IMPROVED CHRONIC ATROPHIC GASTRITIS (RR = 1.84, 95% CI: 1.30-2.61, P < 0.01) AND INTESTINAL METAPLASIA (RR = 1.41, 95% CI: 1.15-1.73, P < 0.01). HOWEVER, IN TERMS OF PREVENTING DYSPLASIA PROGRESSION (RR = 0.86, 95% CI: 0.37-2.00) AND IMPROVING DYSPLASIA (RR = 0.89, 95% CI: 0.47-1.70), HP ERADICATION HAD NO ADVANTAGE COMPARED TO PLACEBO OR NO TREATMENT. CONCLUSIONS: HP ERADICATION THERAPY COULD PREVENT THE PROGRESSION OF GASTRIC PRECANCEROUS LESIONS AND REVERSE THEM. NOTABLY, INTESTINAL METAPLASIA CAN BE REVERSED, BUT THIS MAY ONLY BE APPROPRIATE FOR PATIENTS WITH EPIGENETIC ALTERATIONS AND MILDER LESIONS. 2023 13 4237 42 METHYLATION PATTERN OF THBS1, GATA-4, AND HIC1 IN PEDIATRIC AND ADULT PATIENTS INFECTED WITH HELICOBACTER PYLORI. BACKGROUND: HELICOBACTER PYLORI INFECTION IS USUALLY ACQUIRED IN CHILDHOOD AND PERSISTS INTO ADULTHOOD IF UNTREATED. THE BACTERIUM INDUCES A CHRONIC INFLAMMATORY RESPONSE, WHICH IS ASSOCIATED WITH EPIGENETIC ALTERATIONS IN ONCOGENES, TUMOR-SUPPRESSOR GENES, CELL-CYCLE REGULATORS, AND CELL-ADHESION MOLECULES. AIM: THE AIM OF THIS STUDY WAS TO ANALYZE THE EFFECT OF H. PYLORI INFECTION ON THE METHYLATION STATUS OF THROMBOSPONDIN-1 (THBS1), HYPERMETHYLATED IN CANCER 1 (HIC1) AND GATA BINDING PROTEIN-4 (GATA-4) IN GASTRIC BIOPSY SAMPLES FROM CHILDREN AND ADULTS INFECTED OR UNINFECTED WITH THE BACTERIUM AND IN SAMPLES OBTAINED FROM GASTRIC CANCER PATIENTS. METHODS: THE METHYLATION PATTERN WAS ANALYZED WITH METHYLATION-SPECIFIC PCR. RESULTS: OUR RESULTS SHOWED THAT H. PYLORI INFECTION WAS ASSOCIATED WITH METHYLATION OF THE PROMOTER REGIONS OF THE THBS1 AND GATA-4 GENES IN PEDIATRIC AND ADULT SAMPLES (P < 0.01). HIC1 SHOWED THE LOWEST LEVEL OF METHYLATION, WHICH WAS NOT AN EARLY EVENT DURING GASTRIC CARCINOGENESIS. CONCLUSIONS: THE RESULTS FROM THIS STUDY INDICATE THAT METHYLATION OF THBS1 AND GATA-4 OCCURS IN THE EARLY STAGES OF CHRONIC GASTRITIS AND GASTRIC CANCER IN ASSOCIATION WITH H. PYLORI INFECTION; HOWEVER, IN GASTRIC CANCER SAMPLES, OTHER MECHANISMS COOPERATE WITH THE DOWN-REGULATION OF THESE GENES. METHYLATION OF HIC1 MAY NOT BE THE PRINCIPAL MECHANISM IMPLICATED IN ITS DOWN-REGULATION IN GASTRIC CANCER SAMPLES. 2013 14 4725 37 NORMAL GASTRIC TISSUE HELICOBACTER PYLORI INFECTION IS ASSOCIATED WITH EPIGENETIC AGE ACCELERATION, INCREASED MITOTIC TICK RATE, TISSUE CELL COMPOSITION, AND NATURAL KILLER CELL METHYLATION ALTERATIONS. BACKGROUND: GASTRIC ADENOCARCINOMAS ARE A LEADING CAUSE OF GLOBAL MORTALITY, ASSOCIATED WITH CHRONIC INFECTION WITH HELICOBACTER PYLORI . THE MECHANISMS BY WHICH INFECTION WITH H. PYLORI CONTRIBUTES TO CARCINOGENESIS ARE NOT WELL UNDERSTOOD. RECENT STUDIES FROM SUBJECTS WITH AND WITHOUT GASTRIC CANCER HAVE IDENTIFIED SIGNIFICANT DNA METHYLATION ALTERATIONS IN NORMAL GASTRIC MUCOSA ASSOCIATED WITH H. PYLORI INFECTION AND GASTRIC CANCER RISK. HERE WE FURTHER INVESTIGATED DNA METHYLATION ALTERATIONS IN NORMAL GASTRIC MUCOSA IN GASTRIC CANCER CASES (N = 42) AND CONTROL SUBJECTS (N = 42) WITH H. PYLORI INFECTION DATA. WE ASSESSED TISSUE CELL TYPE COMPOSITION, DNA METHYLATION ALTERATIONS WITHIN CELL POPULATIONS, EPIGENETIC AGING, AND REPETITIVE ELEMENT METHYLATION. RESULTS: IN NORMAL GASTRIC MUCOSA OF BOTH GASTRIC CANCER CASES AND CONTROL SUBJECTS, WE OBSERVED INCREASED EPIGENETIC AGE ACCELERATION ASSOCIATED WITH H. PYLORI INFECTION. WE ALSO OBSERVED AN INCREASED MITOTIC TICK RATE ASSOCIATED WITH H. PYLORI INFECTION IN BOTH GASTRIC CANCER CASES AND CONTROLS. SIGNIFICANT DIFFERENCES IN IMMUNE CELL POPULATIONS ASSOCIATED WITH H. PYLORI INFECTION IN NORMAL TISSUE FROM CANCER CASES AND CONTROLS WERE IDENTIFIED USING DNA METHYLATION CELL TYPE DECONVOLUTION. WE ALSO FOUND NATURAL KILLER CELL-SPECIFIC METHYLATION ALTERATIONS IN NORMAL MUCOSA FROM GASTRIC CANCER PATIENTS WITH H. PYLORI INFECTION. CONCLUSIONS: OUR FINDINGS FROM NORMAL GASTRIC MUCOSA PROVIDE INSIGHT INTO UNDERLYING CELLULAR COMPOSITION AND EPIGENETIC ASPECTS OF H. PYLORI ASSOCIATED GASTRIC CANCER ETIOLOGY. 2023 15 3413 34 HSA-MIR-29C AND HSA-MIR-135B DIFFERENTIAL EXPRESSION AS POTENTIAL BIOMARKER OF GASTRIC CARCINOGENESIS. AIM: TO INVESTIGATE THE EXPRESSION PROFILES OF HSA-MIR-29C AND HSA-MIR-135B IN GASTRIC MUCOSAL SAMPLES AND THEIR VALUES AS GASTRIC CARCINOGENESIS BIOMARKERS. METHODS: THE EXPRESSION LEVELS OF HSA-MIR-29C AND HSA-MIR-135B IN NORMAL GASTRIC MUCOSA, NON-ATROPHIC CHRONIC GASTRITIS, INTESTINAL METAPLASIA AND INTESTINAL-TYPE GASTRIC ADENOCARCINOMA WERE ANALYSED USING QUANTITATIVE REAL-TIME PCR. THE DIFFERENCE BETWEEN HSA-MIR-29C AND HSA-MIR-135B EXPRESSION PROFILES IN THE GROUPED SAMPLES WAS EVALUATED BY ANOVA AND STUDENT'S T-TEST TESTS. THE RESULTS WERE ADJUSTED FOR MULTIPLE TESTING BY USING BONFERRONI'S CORRECTION. P VALUES